Process for ennobling cellulosic materials and product therefrom



Patented Sept. 5, 1933 1,925,914 PROCESS FOR ENNOBLING CELLULOSIC MA- TERIALS AND PRODUCT THEREFROM Waldemar Ziinker, Bar-men,

to Heberlein Patent Corporation,

Germany, assignor New York,

N. 'Y., a corporation of New York No Drawing.

Application April 8, 1933, Serial No. 665,231, and in Germany April 23, 1930 5 Claims. (CI. 91-70) This invention relates to treatment of cellulosic textile materials and particularly to processes for rendering such materials less apt to wrinkle or crease. It also relates to products obtainable thereby. Under textile materials of this kind, I include natural vegetable fibers such as cotton and also artificial silk such as regenerated cellulose and these materials may be treated in any processed form, that is, they may be employed as loose fibers, yarns, fabrics and as finished products worked in any manner.

It is well-known that cellulosic material such as cotton does not have the flexibility of natural silk or wool and is easily creased or crumpled. These characteristics. are especially noticeable in artificial silk. For this reason especially, complete substitution of artificial silk for natural silk has not been feasible in spite of the fact that the strength, washing and many other properties of artificial silk are nearly equal or even excel those of natural silk.

[Attempts have been made to improve the characteristics of these cellulose substances and to make them like the animal fibers. Wellknown finishing agents have been employed, but without satisfactory results. When artificial silk especially is treated with stiffening agents, for instance resins and the like, in accordance with the methods heretofore known, it became soso inelastic and brittle that it was absolutely unsuitable for further working or subsequent use.

The object of the present invention accordingly is to provide a process which will inexpensively and satisfactorily treat the materials mentioned above to render them less apt to wrinkle and to improve other characteristics.

The invention comprises the novel products as well as the novel processes and steps of processes according to which such products are manufactured, the specific embodiments of which are described hereinafter by way of example and in accordance with which I now prefer to practice the invention.

I have found in accordance with this invention that the above-mentioned textiles in any condition of working can be satisfactorily treated to render them less apt to wrinkle and to improve their other characteristics by treating them with products of the type of natural or artificial resins or lacs in the presence of salts, oxides, or hydroxides of bivalent and multivalent metals. These metal compounds are adsorbed by the fiber at least in part and like mordants are stubbornly retained by it. They have the valuable property of preventing an unfavorable penetration of the fiber by the resins. In many cases they directly increase the desired effect. Above all the flexibility is greatly increased. It

is possible to press the fabrics much more firmly together without leaving wrinkles. The fiber 0 does not become sticky so easily and is also fast to' drops. The weight of the treated goods increases considerably depending on the process employed.

In most cases small quantities of metal compounds suffice to produce the desired effect. The treatment is therefore carried out preferably with dilute solutions. In many cases the use of a 0.1%-0.0l% solution is sufllcient for impregnation of the fiber.

It is not necessary to use dissolved oxides or hydroxides for impregnation. Adsorption on the fiber can be brought about through hydrolytic decomposition of soluble salts or such oxides or hydroxides can be produced by volitilization of acid radicals from compounds suitable for this purpose. In this connection substances which are suitable are those in the first place which are soluble and which precipitate insoluble deposits on the fiber through hydrolytic or heat decomposition.

It has been found in accordance with this invention that compounds of aluminum, zirconium, tin, titanium or zinc are exceptionally useful. In addition to the metal compounds set forth above and included inthe claims, it should be understood that other metal compounds could be used, without departing from the scope of the invention, provided they cooperate with the resin to render the fabric less liable to creasing and wrinkling.

The valuable inherent properties of the fiber itself are not covered up by the treatment in accordance with the present invention. 0n the other hand they are improved thereby. The presence of the metal compounds makes it possible to get along with comparatively very small quantities of the treating agents and to obtain effects which are not possible in any other way. This is done without overloading the fiber and making it hard and brittle.

' Various ways have proven suitable for carrying out the process. The textile material may be treated for instance in the form of fibers, yarns or fabrics or apparel made from these products with the metal compounds so that at least part of these compounds is adsorbed by the fiber. The process of fixing these compounds can be assisted by steam and the like. Then there follows a treatment with a solution of the named resinous substances preferably natural or artificial resins or lacs. In many cases the treatment can be made in one and the same bath provided that the metal compounds are soluble in the same solvents as'for the resinous materials used. For instance these metal compounds can be used in organic solvents in which the resins or lacs are also soluble; or they may be converted into aqueous emulsions or colloidal solutions by suitable additions thereto. In some cases if there has been a treatment of the goods with a resinous material which has caused a stiffening, such treatment can be followed by a treatment with one of the metal compounds mentioned in order to remove, at least in part, some of the stiffness.

When artificial resins are employed there is a special advantage in forming these products on the textile material in question, that is, the raw materials for obtaining the artificial resin are simultaneously or consecutively applied to the fiber. With these it is possible to add a catalyst if desired. In most instances, however, the metal compounditself whose presence is necessary for the process, acts as a catalyst. I have further found that catalysts with reducing properties, for instance tin chloride, exercise an exceptionally favorable influence on the later fastness to washing of the effect obtained.

The production of artificial resin on the fiber may take place at any desired stage of the operation and can be effected either after or prior to the adsorption of the metal compounds on the fiber or simultaneously. with it. The formation of the artificial resin is aided after drying by further continued heating, in connection with which as a rule temperatures not essentially higher than-100 C. are required. The kind and duration of this after-drying is governed by the desired degree of stiffening. As artificial resins all of the various known compounds can be employed, for example those made from phenols and aldehydes, as well as thosefrom ureaand aldelwdes and the phthalic anhydride-glycerine condensation known as Glyptal.

In order to increase the adsorption capacity of the fiber which is especially desirable in connection with cotton, it is advisable to subject the fiber, or the fabric mechanically produced therefrom, to a preliminary shrinking treatment with swelling agents such as mercerizing lyes' (caustic soda), acids, zinc chloride and similar salts, cuprammonium and the like. The fiber is thus conditioned so that it can adsorb more metal compounds. Accordingly the effect aimed for, according to my invention, is increased. This combined effect is further increased if the goods are not dried between the preliminary treatment and the main treatment.

It is furthermore advisable to increase the desired swelling of the fiber by the addition of oxidizing agents to the swelling agents. In accordance with my invention I have demonstrated that the addition of oxidizing substances such as sodium peroxide, perborate, etc. is especially favorable in connection with alkali lyes, while in connection with acids, persulfates are recommended. By these additions, there is not only obtained a high degree of swelling but the goods treated in this manner also exhibit a softer, fuller and more wool-like feel after completion.

I give below certain embodiments of the inven tion which are to be considered as illustrative thereof, but the invention is not restricted there- Example 1.A piece of printed satin made from artificial silk viscose is passed on the Jigger through a bath containing a zirconium salt in solution. The temperature of the bath is about 18C.; the time of passage through the bath is about 5 minutes; the concentration of the bath is about 50 grams of zirconium acetate per liter. After wringing, the piece passes through a second bath which contains' an aqueous shellaccontaining borax solution. Thereafter the piece so-treated is dried on a cylinder'drying machine and the goods are then passed over a solid mixture of Japan wax to which, in order to reduce its softening point, paraflin is added. Sufllcient parafiin is added to give a softening point of about 30 C. The shellac-containing borax solution may be produced by dissolving 12 kg. of shellac in a solution of 3 kg. of borax in 40 kg. of water. In place of this a solution of 30 parts 01 shellac in a solution of 6 parts of trisodium phosphate to 100 parts of water may be used. Either of these shellac solutions for the purpose of soft-.

ening may contain about 0.1% of olive oil as an emulsion.

The printed goods as so prepared are provided with a finish which has not been obtained hitherto. This finish is, for example, exceedingly useful for the manufacture of umbrellas. However, goods finished in this manner are also exceptionally valuable for blouses and other wearing apparel.

Example 2.Boiled cotton goods are shrunk in a well-known manner with mercerizing lyecaustic soda solutionof approximately 30 B. with the addition of about 1% .sodium peroxide. The goods remain in this liquor for about 30 seconds at about 15" C. Thereupon they are rinsed and dyed in a manner customary in the textile finishing industry. This is followed by the treatment in accordance with Example 1 without prior drying of the fabric.

I have ascertained in connection with this treatment that the swelling condition caused by the preliminary treatment is splendidly maintained so that a considerably weaker subsequent treatment may be made than otherwise customary in order to make the fabric fast to wrinkling, but without reducing the ability of the fabric to withstand such wrinkling.

Example 3.A piece of artificial silk with cotton warp of a weight of about 12.5 kg. is treated on the jigger at C. in a bath which contains per liter 200 grams of urea and 4 grams of aluminum acetate free from sulfuric acid and also free from aluminum sulfate. After letting the liquid act for 10 minutes, the piece is passed through a second bath for ,5 minute containing 250 com. of 40% formaldehyde solution and 8 grams of aluminum acetate per liter at 60 C.

After letting the material lie or hang in the air for half an hour there takes place a strong condensation between the urea and the formaldehyde. Thereupon the fabric is dried hot at about 80 0., without prior rinsing, in a suitable device such as a drying room, tentering frame or the like.

In order to remove the surplus of the condensation product, the fabric is now treated at 80 C. with a liquor which contains 10 parts of 40% caustic soda solution per liter of water. After a passage of 5 minutes, the piece, after removal of the surplus, shows the desired feel so that it is only necessary to rinse well and to dry. If one works with lesser quantities of the substances mentioned, there suflices in place of the lye treatment, a passage through a boiling 3% soap solution. After this also, as stated above, it is thoroughly washed and dried on the tentering frame. Finally, the fabric is calendered in the customary manner.

Example 4.--40 kg. of urea are dissolved in the cold in 20 liters of 20% formaldehyde'solution. This solution is left to stand for 12 hours and is subsequently diluted with 4 times its quantity of water and thereupon heated to C. A cotton fabric which has been subjected to a prior treatment for A hour with a cold 0.2% aluminum acetate solution, is agitated for a short time in the above hot solution of this pre-condensate and thereupon pressed between a pair of rollers. The fabric while still wet, is left to lie for one hour and is thereupon dried at 80 C. Finally the fabric is calendered in the customary manner.

Example 5.Artificial silk fabric is run into a solution heated to about 70 C. containing 200 grams of urea and 2 grams of aluminum acetate per liter. It is there treated for about V hour. Thereupon the fabric is wrung and passed on a slop-padding machine maldehyde solution. After previous wringing, the fabric is hung up for 2%; hours at room temperature. This is followed by a drying at 80 CQ and then by the customary finishing.

Example 6.A liquor containing 200 grams of urea and 2 grams of tin chloride, is heated to 60 C. and a rayon yarn is agitated in same for hour. After wringing, the further treatment is continued with formaldehyde solution and completed as described in Example 5.

Example 7.-An artificial silk fabric is treated at 60-70 C. for 10 minutes in a bath consisting of an aqueous solution with a content of 200 grams of urea and 2 grams of aluminum acetate per liter. This is followed .by a wringing of the fabric and by a slop-padding with a cold 40% formaldehyde solution which also contains 2 grams of tin chloride per liter. The fabric while still moist, is rolled up and is left to itself while being turned continuously and slowly for 2 hours. Thereupon the fabric is dried in a drying room and is left exposed a short while longer to a temperature of 80 C., whereupon the customary finishing treatment can follow.

Example 8.-20 kg. of urea are dissolved in 50 kg. of 40% formaldehyde solution and to the clearsolution ammonia is added until a. slight alkalinity is shown. The solution is now permitted to stand for 3 hours at room temperature. Thereupon it is acidulated slightly with acetic acid and 175 gr. of aluminum acetate dissolved in 50 ,kg. of water are added. In a bath thus prepared, a cotton-artificial silkmixed fabric is treated for 10 minutes at room temperature, then squeezed and left overnight. This is followed by a hot drying at about 80 C. finally by a calendering on a highly heated calender at about 120 C.

Example 9.-A viscose fabric is put into a bath in the jigger consisting of 200 grams of urea and 4 grams zinc acetate per liter and left therein at 60 C. during 10 minutes. The fabric is then squeezed and passed through a second bath for /2 minute containing 300 com.

of 40% formaldehyde solution and 8 grams. of aluminum acetate per liter at 60 C. The subsequent treatment is done .as stated in Example 3.

The silk, cotton and mixtures thereof finished in accordance with the invention are much more through a cold 40% forflexible. than the corresponding untreated materials. They have acquired properties of animal fibers such as silk and wool. It is possible to crush the fabrics much more firmly together without causing them to wrinkle.

The artificial silk finished in accordance with the invention is very much better adapted for hosiery purposes than such silk hitherto found on the market. It has above all the important property ofgreater mobility (Beweglichkeit) in the meshes and a far greater lack of sensitivity to moisture and street dirt. A special property of the artificial silk obtained in accordance with this process lies in the fact that when moistened with water no rings form on the fabric, whereas when ordinary artificial silk is moistened in this way spots immediately become noticeable which leave rings on drying. Accordingly fabrics and dress materials prepared from it are considerably more valuable than hitherto. The goods thus finished dye excellently almost invariably. It is well-known that dyeing usually entails difficulties in connection with textile goods which have been treated in accordance with other finishing processes.

In general the threads treated in accordance with the present process are not very much harder than the untreated goods. Artificial silk, however, which has been purposely given a hard finish, can be easily softened in a wellknown manne viz. either ina mechanical way by passing through a breaking machine or by a subsequent impregnation with one of the parafline emulsions which are well -known in the trade. Above all, however, the artificial silk fabrics treated in accordance with the new process are very similar to real silk in connec tion with its resistance to crushing. It is a well-known fact that neckties or ribbons made of rayon are crushed and wrinkled after having been tied two or three times, to such an extent that they cannot be used again without first ironing them. As compared with this, genuine silk goods, as is well-known, even after having been tied frequently, possess this defect to a very much lesser extent. By means of the invention disclosed'herein, the same effect is obtained in connection with rayon fabrics. Moreover the properties of artificial silk finished in accordance with the new process, are very similar to theproperties of genuine silk. Thus, for instance, it is well-known that silk ribbons as worn by children in their hair remain upright if they are made of genuine silk, whereas artificial silk ribbons finished in the usual manner fiop after being tied several times. If, however, artificial silk ribbons are used as hair ribbons obtained in connection with this invention, they will stand up in the same manner as genuine silk ribbons.

The expression textile fabric" as used in the .claimsis intended to cover yarn, thread and cloth. The expression "natural or artificial resin is intended to include either of these types of resin mixturesthereof.

While I have described my invention in detail according to the preferred manner of carrying out my process, and producing my product, it will be obvious to those skilled in the art, after understanding my invention, that changes and modifications may be made therein without departing from the spirit or scope of my invention, and I aim in the appended claims to cover all such changes and modifications.

What I claim is:-

1. A process of treating cotton or artificial silk textile fabrics for rendering the fabric less liable to creasing and wrinkling while substantially preserving the suppleness thereof, comprising the steps of impregnating the fabric with a soluble compound of a metal selected from. the group zinc, aluminum, zirconium, tin and titanium, and also impregnating the fabric with a substance capable of forming a water-insoluble resin, and heating the fabric thus treated for forming the insoluble resin and waterinsoluble metal compound on the fabric, the resin and metal compound being present in insufllcient quantities to cause appreciable stiflness.

2. A process in accordance with claim 1 in which the textile fabric is treated with a swelling agent with or without an oxidizing agent in order to permit the fabric to take up the metal compound and resin more readily.

3. A process in accordance with claim 1 in which the resin employed is selected from the group aldehyde-phenol, aldehyde-urea.

4. As a new product a supple textile fabric rendered less liable to creasing and wrinkling impregnated with an insoluble metal compound and impregnated with a water-insoluble resin, the metal of the compound being selected from the group zinc, aluminum, zirconium, tin and titanium the amount of metal compound and resin being insufilcient to cause an appreciable stifiening of the fabric.

5. A product according to claim 4 in which the resin is selected from the group phenol-aldehyde, aldehyde-urea.

- WALDEMAR ziiNKER. 

